1. Field of the Invention
The present invention relates to a photographic light-sensitive material and, more particularly, to a silver halide photographic light-sensitive material having good image sharpness and storage stability.
2. Description of the Related Art
A tabular grain is one of several types of various known forms of silver halide grains for use in a silver halide photographic light-sensitive material.
Methods of manufacturing and techniques of using tabular silver halide grains are already disclosed in, for example, U.S. Pat. Nos. 4,434,226, 4,439,520, 4,414,310, 4,433,048, 4,414,306 and 4,459,353 and JP-A-59-99433 and JP-A-62-209445 ("JP-A-" means Unexamined Published Japanese Patent Application). Known advantages obtained by the tabular silver halide grains are, for instance, an increase in sensitivity including an increase in color sensitization efficiency obtained by a sensitizing dye, an improvement in sensitivity/graininess relationship, an increase in sharpness obtained by specific optical properties of the tabular grains and an increase in covering power.
It has become apparent, however, that the tabular silver halide grain generally has a problem in which a latent image produced by exposure fades as time passes (to be referred to as "latent image fading" hereinafter).
As a means for preventing latent image fading, methods of adding a sulfur-, oxygen- or nitrogen-containing compound are disclosed in, for example, GB-1,308,777, GB-1,335,923, GB-1,353,527, GB-1,378,354, GB-1,386,630, GB-1,387,654, GB-1,389,089, GB-1,391,672, GB-1,390,237, GB-1,394,371, GB-1,412,294, GB-1,458,197, U.S. Pat. No. 3,881,939, U.S. Pat. No. 4,397,942, JP-A-47-37922, JP-A-49-17,720, JP-A-57-22234, JP-A-57-158840, JP-A-58-90634 and JP-A-58-152235; a method of adding a sulfinic acid derivative is disclosed in JP-A-57-104,927 and JP-A-62-21,145; and a method of adding various compounds is disclosed in RD (Research Disclosure) No. 17,643.
The present inventors have studied various methods on the basis of the above finding. With respect to tabular silver halide grains, however, each of the above methods has a drawback of, for example, increasing fog. Therefore, even if latent image fading is improved by these methods, they are still problematic to be put into practical use because of their side effect, i.e., an increase in fog, and an immediate solution of this problem has been desired. In addition, demand has arisen for an improvement in incubation resistance of a tabular emulsion at a high temperature, which is conventionally not at a sufficient level.